Method of introducing volatile matter into lamps and the like



.April '5. 1927.

c, c. VAN VooRl-ns Ms'friov 0F INTRODUCING voLATILE MATTER INT0 LAMPSAND\THE LIKE Filed'Aug. 18. 1923 Patented pr. .5, 1927.

. UNi'r-Ein STATES cLE'rUs CLINTON. VAN vooimis, or' PRINCETON, NEWJERSEY, AssIGNoaro wEsT- 1,623,323 PATE-Nr oi-Fica ING-HOUSE LAMPCOMPANY, A CORPORATION OF PENNSYLVANIA.

METHOD OF INTRDUCING VOLATILE MATTER'INTO LAMPS ANDTHE LIKE.

iippiicaaon sied Aug-ust 1s, 1923. serial 'No'. 655097.

This invention relates to the manufacture of gaseous discharge lamps andmore particularly .to a method of and means for the introduction ofpotassium or othersuitable vapor therein.

It is becoming well known that b y introducing the vapor of metallicpotassium, so dium or the like into an electric lamp filled with a gassuch as neon, certain-distmct advantages are obtained. D ue to somepeculiar phenomenon, the introduction of a vapor of an element of theclass of potassium, reduces the starting and operating voltages of gasglow lamps to a minimum and in addition functions as an eiiicientclean-up agent.

It isan object ofthe invention to devise a method whereby theintroduction of such metallic va ors may be facilitated.

It is a f rther object to devise an appa ratus by which the method maybe carried of apparatus by means of which the metallic vapors maybeintroduced into the lamp;

Fig. 2 is a sectionV thereof taken on 'tlie line II-II of Fig. 1,looking in the direction of 'the arrows Fig. 3 is asectional view of oneform 1n which the metal may be prepared for intro duction, and Fig. 4 isa view of another form in which v the metal may be prepared showing amangenerally designated 16 and-adapted to slide therein on projectionsor guides 18, back and ner in which it may be so prepared.

Fig. 5 is a section on the line V Fig. 1.

In my Voi co ending a 'w'cation, 'Seri PP 569,861, file June 21,??1922,entitled Manufacture ofcelectric lamps and the like, and assigned to theWestinghouse Lamp I have disclosed a method of and an apparatus fbi'the, introduction of an unstable volatile andin certain respects, themethod and ap'-y paratus of this application may be considered asmodifications.

Numerous difficulties are encountered m introducing an alkali metalorits vapor into av lamp. These dilcultles are due almost entirely to,the chemical activity of the metal which, in the case of potassium,

renders it almost impossible of inanil pj ilah haust.

material in an electric lamp'--- 20 .in any appropriate manner, but,

such metals volatilize at extremely low temperatures, it is not easy tomaintain the metal in a non-volatilized or stable state While baking outthe lamp during the ex- By myinvention I render it practical to bake outthe lamp during the exhausting operation and at the. same timefacilitate the' introduction of the alkalil metal vapor at thedesiredlperiod.

In carrying out the operation, I so preparethe metal to be introduced,hereinafter specified as potassium, that itwill be relativelystable-under ordinary conditions and vso .dispose it with respect to thelamp that it may be readily positioned for volatilization into the lampand where the hot 'exhaust from thelatter or from the baking outapparatus (not shown) willnot come into Contact with it.

In Fig. 1 I have showh one forml which` my invention embraces andtherein have .diagrammatically illustrated a manner of hereinafterdescribed. l

Within the tube 8 is positioned a carrier forth between the positionsshow n in full and dotted lines. The recess 14 permits the carrier 16 top esition itself as shown'in the dotted lines. recessed cradle portion20 of glass or like material and a portion 22 ofsoft iron orthe likeattached thereto for cooperation with a magnet 24, whereby the carriermay be moved from end to end of the tube upon movementla'of -the'magnet.The cradle 20- f is provided wf'ith the'recess to carry a. pellet o`rother `forni of the material to be volatilizedfyintothe lamp.

Thefipellet of potassium, --generally desi he carrier may comprise a lioo los

nated 26, may be displaced from the crad e preferlarge abiy, I makethe't'ube 8 rgund and cross sectional area compared tothe same area ofcarrier 16so that by moving the magnet 24 to one side orcireumferentially of the tube 8 as shown "the arrow in Fig. 5, I roll orrock the cradle 16 sufficiently to displace the pellet therefrom. Theprojections 18, in addition to serving as guides, act to preventpremature rotation of the carrier.

In order to insure that'the potassium will be volatilized into the lampsand not into the main 6, I prevent the escape of any matter into themain, While the potassiumf is being volatilized, by a peculiarexpedient. At the base of the main 6 and adjacent to the manifoldconnection, I form a recess 28 large enough to receive a stopper or plug30, preferably comprising a glass capsule enclosing a soft iron rod,adapted to be lifted -from the recess and placed within a constrictedportion 32of the main 6 by meansof an electro-magnet 34. The glassenclosed stopper maybe ground to fit the constricted portion 32 of themain 6 snugly and effectually closes the manifold 2 from the main 6 asshown in dotted lines. When it is desired to move the stopper 30 fromwithin the recess`28 to the constriction 32 or vice versa, it is merelynecessa/ryptoenergize the magnet 34, bring it into positign adacent thesto per andV vthen by an vupwar and Vcircumferential movement raise thestopper from the recess 28 and move it to a position over theconstriction 32 into whichl it may then be readily deposited. Othermagnetic or electrical means may be substituted for the electro-magnetas will be obvious.

After the lamps have been connected lto the manifold, the ground glassstopper 12 is removed, a pellet or other form of the material to bevolatilized is positioned in rial.

the carrier cradleV 20, which is inserted within the tube 8, the stoppergreased with vaseline or the like and replaced. The lamps may now beexhausted as desired, preferably with bakin When the desired degree ofexhaustion o the lamps is reached, the magnet 24 is energized andmanipulated to precipitate the Apotassium lpellet into the main 6 andthe magnet 34 is energized to lift the plug 30 from its recess 28 and toppsition it in the eonstricted portion 32.

eat may` be applied, as shown at 36, to volatilize the potassium.

.As will be apparent, any desired gas may be put into the lamps beforeor after volatilization of the potassium or other mate- In thisconnection, however, I prefer to fill thelamps, to the desired pressurewith neon gas, after the potassium has .beenl volatili'zed. as in thisWay I am enabled to A vaporize the potassium inoreeasily.

In Figa3 I have illustrated a glass .encapsulated potassium pellet whichis formed. as described 4in my copendingf;application:

1,ea3,sas

above referred to except that prior to the insertion o f the capsulewithin the cradle of the carrier, I break off the ends, of the to theWestinghouse Lamp Company. In.

this type, the potassium is covered with such a metal as lead in stripform -until ready'ifor use, whereupon vit is cutY 4into convenientlengths by dull shears as shown at 40 and 42. By cutting the strip witha dull instrument, the lead or other metal encasing the potassium'isdrawn in as at 44 hermetically sealing both severed ends. When heatedwithin the manifold, the potassium volatilizes at a lower temperaturethan the lead and, owing to its greater coeicient of expansio'n at thattemperature, bursts from its -lead confines.

-While .I have illustrated and described what I may consider a preferredform of my invention, many modifications ther-ectl may be made withinthe spirit andscope of the appended/claims.

What is claiianed is:

1. rlhe combination with lan exhaust system for evacuated containers, ofmeans for Vintroducing volatile substances into said system at a pointremote from said containers and means for subsequently transferring saidmaterial in a solid condition to a position adjacent said containers.

2. The combination with an exhaust apparatus for evacuated containersadapted to .be baked out during evacuation, of means for introducing avolatile substance into said apparatus and maintaining it in a cooledportion thereof during the bakingoutfop'eration and means forsubsequently transferrin'v said substance without vola-4 tilization tereof to another part of.said` l apparatus.' y

3. The combination with an exhaust apparatus for evacuated containersadapted to be baked out during evacuation, of means for vintroducing avolatile substance into 'said apparatus and maintaining it in va cooledportion thereof while said containers are ",being baked out and meansarranged exteriorly of Vsaid system for subsequently transferring saidsubstance without volatilization thereof. to another part of saidapparatus.

4. The combination with an exhaust apparatus for evacuated containersadapted to be baked out 'duringevaeuation and a pump connectiontherefor, of means for introducparatus and maintaining it in a cooledpor-v tion thereof while said containers 'are being baked out, means forsubsequently transferring said substance without volatihzation thereofto another part of said apparatus,v

means for sealing said materiai from the pump connection and means forvolatilizing said material intosaid container.

G. The combination withan exhaust apparatus having an exhaust manifoldand a pump connection, of" means for introducing a volatile substanceinto-said pump conneetion at a point remote from said manifold, andelectromagnetic means for subsequently transferring said substance tosaid manifold.

7. The method of introducing a volatile substance into an evacuateddevice which consists in introducing said substance into an exhaustsystem communicating with said device, at a point remote therefrom,evacuating the device. transferring the substance in a solid conditionto a point adjacent said device and volatilizing it into said device.

8. The method of introducing the vapor of a volatile substance Within anhermatically sealed vessel which comprises posi- .tioning said substanceat an inactive posi-v tion Within a portion of said vessel, sealing saidvessel hermetically, performing preliminary operations upon said vessel,bodily repositioning said substance to an active position whilemaintaining said seal and volatilizing said substance.

9. The method of introducing the vapor of a volatile substance within anhermctically sealed vessel which comprises positioning said substance atan inactive position within a portion of said vessel, sealing saidvessel hermetically, evacuating said vessel, repositioning saidsubstance Without volati.iza

tion thereof to an active`.posit'ion while' maintaining said seal andthereafter volatihzlng sald substance.

10. An exhaust system-for an evacuated .container having a pumpconnection, a valve located wholly Within said pump connection, a seatfor said valve and means external to the system for raising saidvalve'from its seat and depositing itl at a point out of the path ofcommunication and container. i

11. An exhaust system for an evacuated container having a pumpconnection. a valve located wholly within saidv pump. connection, a seatfor said valve and electromagnetic means for lifting said valve from itsseat and depositing it at a point in said pump connection out of thepath of communication between the pump and container.

between the' pump In testimony whereof, I have hereunto A subscribed myname this sixteenth day of August, 1923.

citrus CuNToNvN voonms.

